1
0
mirror of git://projects.qi-hardware.com/ben-wpan.git synced 2024-09-29 16:27:37 +03:00
ben-wpan/atusb/fw2/atusb.c
Werner Almesberger 1c004ee2d2 atusb/fw2: moved board-specific functions (SPI, RF reset) out of main()
- Makefile (OBJS): added spi.o
- spi.h, spi.c, atusb.c: moved SPI functions to new file
- spi.h (spi), spi.c (spi), atusb.c (main): renamed function "spi" to
  "spi_io"
- atusb.c (reset_rf, main): moved transceiver reset to separate function
2011-02-08 21:32:24 -03:00

76 lines
1.2 KiB
C

#include <stdint.h>
#include <avr/io.h>
#define F_CPU 8000000UL
#include <util/delay.h>
#include "freakusb.h"
#include "at86rf230.h"
#include "io.h"
#include "spi.h"
void reset_rf(void);
void reset_rf(void)
{
/* AT86RF231 data sheet, 12.4.13, reset pulse width: 625 ns (min) */
CLR(nRST_RF);
_delay_us(1);
SET(nRST_RF);
/* 12.4.14: SPI access latency after reset: 625 ns (min) */
_delay_us(1);
}
int main(void)
{
/* We start with a 1 MHz/8 clock. Disable the prescaler. */
CLKPR = 1 << CLKPCE;
CLKPR = 0;
/* set up all the outputs; default port value is 0 */
OUT(LED);
OUT(nRST_RF); /* resets the transceiver */
OUT(SLP_TR);
spi_init();
reset_rf();
/* switch CLKM to 8 MHz */
/*
* @@@ Note: Atmel advise against changing the external clock in
* mid-flight. We should therefore switch to the RC clock first, then
* crank up the external clock, and finally switch back to the external
* clock. The clock switching procedure is described in the ATmega32U2
* data sheet in secton 8.2.2.
*/
spi_begin();
spi_send(AT86RF230_REG_WRITE | REG_TRX_CTRL_0);
spi_send(CLKM_CTRL_8MHz);
spi_end();
/* now we should be at 8 MHz */
SET(LED);
_delay_ms(100);
CLR(LED);
usb_init();
hw_init();
while (1)
usb_poll();
}